Gas purge device and gas purging method

ABSTRACT

A gas purge device includes a first nozzle and a gas gate. The first nozzle is coupled to a front-opening unified pod (FOUP) through a first port of the FOUP. The gas gate is coupled to the first nozzle via a first pipe. The gas gate includes a first mass flow controller (MFC), a second MFC, and a first switch unit. The first MFC is configured to control a first flow of a first gas. The second MFC is configured to control a second flow of a second gas. The first switch unit is coupled to the first MFC and the second MFC, and is configured to provide the first gas to the first nozzle through the first pipe or receive the second gas from the first nozzle through the first pipe according to a process configuration.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional application of U.S. Non-Provisionalapplication Ser. No. 17/077,849 filed Oct. 22, 2020, which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to a gas purge device and a gas purgemethod, and more particularly, to a gas purge device and a gas purgemethod for purging a wafer container to clean wafers.

DISCUSSION OF THE BACKGROUND

In the semiconductor industry, a wafer container is used for storingwafers. During the processing of the wafers, airborne molecularcontamination (AMC) can enter the wafer container and damage the wafersin the wafer container. Various techniques that use gas to purge AMCfrom the wafer container have been introduced. However, differentpurging processes with different gases must be performed on differentdevices, which is very inefficient and high in cost.

This Discussion of the Background section is provided for backgroundinformation only. The statements in this Discussion of the Backgroundare not an admission that the subject matter disclosed in this sectionconstitutes prior art to the present disclosure, and no part of thisDiscussion of the Background section may be used as an admission thatany part of this application, including this Discussion of theBackground section, constitutes prior art to the present disclosure.

SUMMARY

One aspect of the present disclosure provides a gas purge device,including a first nozzle and a gas gate. The first nozzle is coupled toa front-opening unified pod (FOUP) through a first port of the FOUP. Thegas gate is coupled to the first nozzle via a first pipe. The gas gateincludes a first mass flow controller (MFC), a second MFC, and a firstswitch unit. The first MFC is configured to control a first flow of afirst gas. The second MFC is configured to control a second flow of asecond gas. The first switch unit is coupled to the first MFC and thesecond MFC, and is configured to provide the first gas to the firstnozzle through the first pipe or receive the second gas from the firstnozzle through the first pipe according to a process configuration.

In some embodiments, the gas purge device further includes a secondnozzle coupled to the FOUP. The gas gate is further coupled to thesecond nozzle via a second pipe. The gas gate further includes a thirdMFC, a fourth MFC, and a second switch unit. The third MFC is configuredto control a third flow of the first gas. The fourth MFC is configuredto control a fourth flow of the second gas. The second switch unit iscoupled to the third MFC and the fourth MFC, and configured to providethe first gas to the second nozzle through the second pipe or receivethe second gas from the second nozzle through the second pipe accordingto the process configuration.

In some embodiments, when the first gas is provided to the first nozzleby the first switch unit, the second gas is received from the secondnozzle by the second switch unit.

In some embodiments, the gas purge device further includes a thirdnozzle coupled to the FOUP and a fourth nozzle coupled to the FOUP. Thegas gate is further coupled to the third nozzle and the fourth nozzlevia a third pipe and a fourth pipe, respectively. The gas gate furtherincludes a fifth MFC, a sixth MFC, a seventh MFC, an eighth MFC, a thirdswitch unit and a fourth switch unit. The fifth MFC is configured tocontrol a fifth flow of the first gas. The sixth MFC is configured tocontrol a sixth flow of the second gas. The seventh MFC is configured tocontrol a seventh flow of the first gas. The eighth MFC is configured tocontrol an eighth flow of the second gas. The third switch unit iscoupled to the fifth MFC and the sixth MFC, and configured to providethe first gas to the third nozzle through the third pipe or receive thesecond gas from the third nozzle through the third pipe according to theprocess configuration. The fourth switch unit is coupled to the seventhMFC and the eighth MFC, and configured to provide the first gas to thefourth nozzle through the fourth pipe or receive the second gas from thefourth nozzle through the fourth pipe according to the processconfiguration.

In some embodiments, the first gas is provided to the first nozzle bythe first switch unit, and the second gas is received from the secondnozzle, the third nozzle and the fourth nozzle by the second switchunit, the third switch unit and the fourth switch unit, respectively.

In some embodiments, the first gas is provided to the first nozzle andthe third nozzle by the first switch unit and the third switch unit,respectively, and the second gas is received from the second nozzle andthe fourth nozzle by the second switch unit and the fourth switch unit,respectively.

In some embodiments, the first gas is provided to the first nozzle, thethird nozzle and the fourth nozzle by the first switch unit, the thirdswitch unit and the fourth switch unit, respectively, and the second gasis received from the second nozzle by the second switch unit.

In some embodiments, the gas gate further includes a controller. Thecontroller is configured to control the first switch unit, the secondswitch unit, the third switch unit, the fourth switch unit, the firstMFC, the second MFC, the third MFC, the fourth MFC, the fifth MFC, thesixth MFC, the seventh MFC and the eighth MFC.

In some embodiments, the controller is further configured to receive asensing signal generated by a sensor, wherein the sensor is configuredto sense humidity, a concentration of the first gas, and/or aconcentration of second gas of the FOUP. The controller further controlsthe first switch unit, the second switch unit, the third switch unit,the fourth switch unit, the first MFC, the second MFC, the third MFC,the fourth MFC, the fifth MFC, the sixth MFC, the seventh MFC and theeighth MFC according to the sensing signal.

In some embodiments, the controller is implemented by a programmablelogic controller (PLC).

In some embodiments, the gas purge device further includes a mechanismconfigured to be clamped and connected to the FOUP.

In some embodiments, the gas purge device is configured to provide thefirst gas to wafers in the FOUP. The wafers are 12-inch and/or 18-inchwafers.

In some embodiments, the first switch unit includes a first valve and asecond valve. The first valve is configured to be opened to provide thefirst gas to the first nozzle. The second valve is configured to beopened to receive the second gas from the first nozzle. When the firstvalve is open, the second valve is closed. When the first valve isclosed, the second valve is open.

In some embodiments, the gas gate further includes a ninth MFCconfigured to control a ninth flow of a third gas. The third gas isdifferent from the first gas and the second gas. The first switch unitis further coupled to the ninth MFC, and configured to provide the thirdgas to the first nozzle through the first pipe.

In some embodiments, the gas gate further includes a tenth MFCconfigured to control a tenth flow of a fourth gas. The fourth gas isdifferent from the first gas, the second gas and the third gas. Thefirst switch unit is further coupled to the tenth MFC, and configured toprovide the fourth gas to the first nozzle through the first pipe.

Another aspect of the present disclosure provides a method including thefollowing operations: receiving, by a gas purge device, a front-openingunified pod (FOUP) with wafers therein; determining a first number offirst intake ports of the gas purge device and a second number of secondexhaust ports of the gas purge device; and, based on the first numberand the second number, cleaning the wafers in the FOUP. Cleaning thewafers includes: providing, by a gas gate of the gas purge device, afirst flow of a first gas through the first intake ports to the FOUP;receiving, by the gas gate, a second flow of a second gas from the FOUPthrough the second exhaust ports.

In some embodiments, the cleaning of the wafer further includes:controlling the first number of switch units connected to the firstintake ports to select a first gas source for providing the first gas tothe FOUP; and controlling the second number of the switch unitsconnected to the second exhaust ports to select a gas tank for receivingthe second gas from the FOUP.

In some embodiments, the method further includes: determining the firstflow of the first gas and the second flow of the second gas. Cleaningthe wafers further includes: setting the first number of first mass flowcontrollers (MFCs) to have a first overall flow equal to the first flow;and setting the second number of second MFCs to have a second overallflow equal to the second flow. The first MFCs are connected to the firstgas source, and the second MFCs are connected to the gas tank. A sum ofthe first number and the second number is equal to 4, and the firstnumber and the second are greater than 0.

In some embodiments, the method further includes: determining a thirdnumber of third intake ports of the gas purge device. Cleaning thewafers further includes: controlling the third number of switching unitsconnected to the third intake port to select a second gas source forproviding the third gas to the FOUP; setting the third number of thirdMFCs to have a third overall flow equal to the third flow; andproviding, by the gas gate, the third flow of a third gas through thethird intake ports to the FOUP.

In some embodiments, the receiving of the FOUP includes: clamping theFOUP and the gas purge device by a clamper.

The foregoing has outlined rather broadly the features and technicaladvantages of the present disclosure in order that the detaileddescription of the disclosure that follows may be better understood.Additional features and advantages of the disclosure will be describedhereinafter, and form the subject of the claims of the disclosure. Itshould be appreciated by those skilled in the art that the conceptionand specific embodiment disclosed may be readily utilized as a basis formodifying or designing other structures or processes for carrying outthe same purposes of the present disclosure. It should also be realizedby those skilled in the art that such equivalent constructions do notdepart from the spirit and scope of the disclosure as set forth in theappended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present disclosure may be derivedby referring to the detailed description and claims when considered inconnection with the Figures, where like reference numbers refer tosimilar elements throughout the Figures.

FIG. 1 is a schematic view of a front-opening unified pod (FOUP)according to some embodiments of the present disclosure.

FIG. 2 is a schematic view of a bottom of the FOUP according to someembodiments of the present disclosure.

FIG. 3 is a block diagram of a side view of the bottom of the FOUPaccording to some embodiments of the present disclosure.

FIG. 4 is a schematic diagram of a gas pipe of the FOUP according tosome embodiments of the present disclosure.

FIG. 5 is a schematic view of gas flows in the FOUP according to someembodiments of the present disclosure.

FIG. 6 is a schematic diagram of a gas purge device with the FOUPaccording to some embodiments of the present disclosure.

FIG. 7 is a schematic diagram of the connection from a gas source and agas tank to the bottom of the FOUP according to some embodiments of thepresent disclosure.

FIG. 8 is a schematic diagram of a switch unit of the gas purge deviceaccording to some embodiments of the present disclosure.

FIG. 9 is a block diagram of a gas gate of the gas purge deviceaccording to some embodiments of the present disclosure.

FIG. 10 is a block diagram of the gas gate of the gas purge deviceaccording to other embodiments of the present disclosure.

FIG. 11 is a schematic view of operations of the gas gate deviceaccording to some embodiments of the present disclosure.

FIG. 12 is a schematic view of operations of the gas gate deviceaccording to other embodiments of the present disclosure.

FIG. 13 is a schematic view of operations of the gas gate deviceaccording to various embodiments of the present disclosure.

FIG. 14 is a schematic view of operations of the gas gate deviceaccording to alternative embodiments of the present disclosure.

FIG. 15 is a schematic diagram of the gas purge device according toother embodiments of the present disclosure.

FIG. 16 is a schematic diagram of a gas purge device with the FOUPaccording to other embodiments of the present disclosure.

FIG. 17 , FIG. 18 , FIG. 19 and FIG. 20 are flowchart diagrams of thegas purge method according to some embodiments of the presentdisclosure.

DETAILED DESCRIPTION

Embodiments, or examples, of the disclosure illustrated in the drawingsare now described using specific language. It shall be understood thatno limitation of the scope of the disclosure is hereby intended. Anyalteration or modification of the described embodiments, and any furtherapplications of principles described in this document, are to beconsidered as normally occurring to one of ordinary skill in the art towhich the disclosure relates. Reference numerals may be repeatedthroughout the embodiments, but this does not necessarily mean thatfeature(s) of one embodiment apply to another embodiment, even if theyshare the same reference numeral.

It shall be understood that, although the terms first, second, third,etc. may be used herein to describe various elements, components,regions, layers or sections, these elements, components, regions, layersor sections are not limited by these terms. Rather, these terms aremerely used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of the present inventive concept.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting to thepresent inventive concept. As used herein, the singular forms “a,” “an”and “the” are intended to include the plural forms as well, unless thecontext clearly indicates otherwise. It shall be further understood thatthe terms “comprises” and “comprising,” when used in this specification,point out the presence of stated features, integers, steps, operations,elements, or components, but do not preclude the presence or addition ofone or more other features, integers, steps, operations, elements,components, or groups thereof.

FIG. 1 is a schematic view of a front-opening unified pod (FOUP)according to some embodiments of the present disclosure. During thesemiconductor manufacturing process, the wafers 105 are transported andstored inside the FOUP 100, as illustrated in FIG. 1 . The FOUP 100includes a container 120 and a door 140. The container 120 is configuredto contain the wafers 105, and the door 140 is configured to seal thecontainer 120 so as to form an independent environment in the container120 for the wafers 105. In other words, when the container 120 is sealedby the door 140, the wafers 105 are isolated from environmentalcontamination, such as undesired particles. The FOUP 100 furtherincludes gas pipes 130 and 131, which are configured to facilitate gasflow in the container 120.

In some embodiments, the configuration of the FOUP 100 complies with theSEMI-standard. The FOUP 100 is able to carry 12-inch wafers 105 and/or18-inch wafers 105, and the wafers 105 are stacked from a bottom 120 aof the FOUP 100.

FIG. 2 is a schematic view of the bottom 120 a of the FOUP 100 accordingto some embodiments of the present disclosure. During the semiconductormanufacturing process, the bottom 120 a of the FOUP 100 serves as aninterface to the semiconductor equipment for the semiconductormanufacturing process, for example, a gas purge device for purging theFOUP 100, as illustrated in FIG. 6 below.

As illustrated in FIG. 2 , a port 121, a port 122, a port 123, a port124 and a coupling groove 125 are disposed at the bottom 120 a. Theports 121 to 124 are configured to transport gas for the semiconductormanufacturing process, and the coupling groove 125 is configured to beclamped so as to fix the FOUP 100 and prevent the FOUP 100 from movingduring processing. For example, in previous configurations, when thewafer container is purged using a large flow of gas, the wafer containermight vibrate during purging. However, when the FOUP 100 is clamped, theFOUP 100 can be secured so as to prevent movement.

FIG. 3 illustrates a side view of the bottom 120 a of the FOUP 100. Theports 121 to 124 penetrate a thickness of the bottom 120 a and connecttwo surfaces of the bottom 120 a. Therefore, the gas can be transportedthrough the ports 121 to 124 between two surfaces of the bottom 120 a.The coupling groove 125 recesses from a bottom surface of the bottom 120a so as to be easily clamped by another device.

FIG. 4 illustrates the gas pipe 130 of the FOUP 100. In someembodiments, the gas pipe 130 is identical to the gas pipes 131. The gaspipe 130 includes openings 130 a. The gas pipe 130 is configured toimport gas to the container 120 or remove gas from the container 120.When the gas pipe 130 imports gas into the container 120, the gas isintroduced into the container 120 through the openings 130 a, and thegas pipe 130 is also referred to as an inlet pipe. When the gas pipe 130removes gas from the container 120, the gas leaves the container 120through the openings 130 a, and the gas pipe 130 is also referred to asan outlet pipe.

FIG. 5 illustrates a schematic view of gas flows in the FOUP 100. Insome embodiments, the ports 121 and 122 correspond to the gas pipes 130and 131, respectively. In order to prevent the transportation of wafers105 from blocking, there is no gas pipe corresponds to the ports 123 and124, in which the ports 123 and 124 are closer to the door 140 than theports 121 and 122.

During the gas purge process for cleaning the wafers 105, the gas isprovided to the container 120 by the inlet pipe (i.e., the gas pipe 130in FIG. 5 ) and removed by the outlet pipe (i.e., the gas pipe 131 inFIG. 5 ). The gas pipe 130 and the gas pipe 131 extend vertically abovethe bottom 120 a. The openings 130 a and the openings 131 a aresubstantially aligned with each other, and each pair of openings 130a/131 a is substantially aligned with a space between the wafers 105.When the gas flow is distributed by the opening 130 a along the spacebetween the wafers 105, the space between the wafers 105 directs the gasflow to the opening 131 a. Therefore, the space between the wafers ispurged of contaminants, and the top and bottom surfaces of the wafers105 can be cleaned by the gas flow.

FIG. 6 is a schematic diagram of a gas purge device 600 with the FOUP100 according to some embodiments of the present disclosure. The gaspurge device 600 is configured to perform a gas purge process on thewafers 105 in the FOUP 100 for cleaning the wafers 105. The gas purgedevice 600 receives the FOUP 100 such that the bottom 120 a of the FOUP100 serves as an interface to the gas purge device 600. The gas istransported through the bottom 120 a. In some embodiments, the gas purgedevice 600 connects to a gas source 600 a so as to provide gas, andconnects to a gas tank 600 b so as to remove the gas.

The gas purge device 600 includes a gas gate 620, a mechanism 640, apipe 601, a pipe 602, a pipe 603 and a pipe 604. The pipes 601 to 604connect to nozzles 611 to 614, respectively, and the nozzles 611 to 614correspond to the ports 121 to 124 on the bottom 120 a of the FOUP 100.The gas gate 620 couples the gas source 600 a and the gas tank 600 b tothe pipes 601 to 604 in order to connect the gas source 600 a and thegas tank 600 b to the FOUP 100. The mechanism 640 is configured toconnect to the coupling groove 125 of the bottom 120 a of the FOUP 100so as to make the FOUP 100 unable to move during the gas purge process.In some embodiments, the mechanism 640 is connected to the couplinggroove 125 by a clamper (not shown in the drawings). The damper isconfigured to clamp the mechanism 640 of the gas purge device 600 andthe coupling groove 125 of the FOUP 100. In this way, the FOUP 100 canstay still on the gas purge device 600 during the gas purge process.

The gas gate 620 includes a controller 630 configured to control the gasprovided to the FOUP 100 and removed from the FOUP 100. Morespecifically, the controller 630 selects the gas source 600 a or the gastank 600 b to be connected to the pipes 601 to 604. In some embodiments,the controller 630 is implemented by a programmable logic controller(PLC).

In some embodiments, the controller 630 may include a central processingunit (CPU), a microcontroller unit (MCU), other hardware circuitelements capable of executing relevant instructions, or a combination ofcomputing circuits that are well-known by those skilled in the art basedon the above disclosures.

In some embodiments, the gas source 600 a is a gas cylinder whichcontains noble gas such as argon (Ar) or helium (He). In otherembodiments, the gas source 600 a contains nitrogen (N). The gasprovided by the gas source 600 a is introduced into the FOUP 100 andreplaces the atmosphere in the FOUP 100. In some embodiments, the gastank 600 b is a vacuum pump, and the vacuum pump is configured to createa vacuum to pull the gas out of the FOUP 100 and to maintain a pressurewithin the FOUP 100. The gases mentioned above are provided forillustrative purposes. Various gases provided by the gas source 600 arewithin the contemplated scope of the present disclosure. For example, invarious embodiments, the gas source 600 a contains oxygen (O₂) or mixedair without water vapor.

FIG. 7 illustrates the connection from the gas source 600 a and the gastank 600 b to the bottom 120 a of the FOUP 100. As illustrated in FIG. 7, the gas source 600 a and the gas tank 600 b are connected to the ports121 to 124 of the bottom 120 a through the gas gate 620. To facilitateunderstanding, the pipes 601 to 604 and the nozzles 611 to 614 areomitted from FIG. 7 .

The gas gate 620 includes switch units 621 to 624 configured to controlthe gas flow from the gas source 600 a to the FOUP 100, or control thegas flow from the FOUP 100 to the gas tank 600 b. Each of the switchunits 621 to 624 connects the gas source 600 a and the gas tank 600 b tothe ports 121 to 124, respectively. Therefore, the ports 121 to 124 maybe controlled by the switch units 621 to 624 to connect to the gassource 600 a or the gas tank 600 b. In other words, the ports 121 to 124can serve as intake ports or exhaust ports.

In some embodiments, the controller 630 determines whether the ports 121to 124 are to serve as the intake port or the exhaust port according toa process configuration of the process being performed on the wafers105. For example, in an embodiment, a cleaning process needs two intakeports and two exhaust ports, and the controller 630 controls the switchunits 621 and 622 to connect the gas source 600 a to the ports 121 and122, and controls the switch units 623 and 624 to connect the gas tank600 b to the ports 123 and 124. In other words, the controller 630determines a number of intake ports and a number of exhaust portsaccording to the process configuration of the cleaning process, and thegas purge device 600 performs the cleaning process based on the numberof intake ports and the number of exhaust ports.

As shown in FIG. 7 , each of the switch units 621 to 624 is furthercoupled to a pair of mass flow controllers (MFCs). For illustration, theswitch unit 621 is coupled to an MFC 621 a and an MFC 621 b, the switchunit 622 is coupled to an MFC 622 a and an MFC 622 b, the switch unit623 is coupled to an MFC 623 a and an MFC 623 b, and the switch unit 624is coupled to an MFC 624 a and an MFC 624 b.

In some embodiments, the controller 630 determines the gas flow throughthe ports 121 to 124 according to the process configuration, and thecontroller 630 further controls the MFCs 621 a, 621 b, 622 a, 622 b, 623a, 623 b, 624 a and 624 b to cause the desired gas flows.

The MFCs 621 a, 622 a, 623 a and 624 a connect the gas source 600 a tothe switch units 621, 622, 623 and 624, respectively. The MFCs 621 a,622 a, 623 a and 624 a are configured to control and measure the gasflow from the gas source 600 a to the switch units 621, 622, 623 and624, respectively.

The MFCs 621 b, 622 b, 623 b and 624 b connect the gas tank 600 b to theswitch units 621, 622, 623 and 624, respectively. The MFCs 621 b, 622 b,623 b and 624 b are configured to control and measure the gas flow fromthe switch units 621, 622, 623 and 624 to the gas tank 600 b,respectively.

After the controller 630 determines the gas flow through the ports 121to 124, the number of intake ports, and the number of exhaust ports, theoverall gas flow of the gas provided by the gas source 600 a and theoverall gas flow of the gas removed from the FOUP 100 are determined.For example, when the number of intake ports and the number of exhaustports are determined to be 2 and 2, respectively, the controller 630controls 2 switch units (such as the switch units 621 and 622) to selectthe gas source 600 a for providing the gas, and controls the other 2switch units 623 and 624 to select the gas tank 600 b for removing thegas from the FOUP 100. The controller 630 further controls the MFC 621 aand the MFC 622 a to cause the total gas flow to equal the determinedoverall gas flow of the gas provided by the gas source 600 a, andcontrols the MFC 623 b and the MFC 624 b to cause the total gas flow toequal the determined overall gas flow of the gas removed to the gas tank600 b. In this example, the MFCs 621 b, 622 b, 623 a and 624 a are idleor set to have a gas flow equal to 0.

FIG. 8 illustrates the switch unit 621 according to some embodiments ofthe present disclosure. The switch unit 621 includes a valve V1 and avalve V2. The switch unit 621 connects to the MFC 621 a through thevalve V1, and connects to the MFC 621 b through the valve V2.

When the port 121 is determined to be an intake port, the switch unit621 is controlled to connect to the MFC 621 a and disconnect from theMFC 621 b. Under this condition, the valve V1 is open, and the valve V2is closed.

When the port 121 is determined to be an exhaust port, the switch unit621 is controlled to connect to the MFC 621 b and disconnect from theMFC 621 a. Under this condition, the valve V2 is open, and the valve V1is closed.

The valve V1 and the valve V2 cannot be open at the same time. However,when the cleaning process does not need the port 121 to transport gas,the valve V1 and the valve V2 are both closed.

Each of switch units 622 to 624 also includes two valves. The operationsof the switch units 622 to 624 are similar to those of the switch unit621. Thus, descriptions of the operations of valves of the switch units622 to 624 are not repeated herein.

FIG. 9 illustrates a block diagram of a gas gate 620 according to someembodiments of the present disclosure. The switch units 621 to 624 andthe MFCs 621 a, 621 b, 622 a, 622 b, 623 a, 623 b, 624 a and 624 b areelectrically coupled to the controller 630 and are controlled by thecontroller 630.

In some embodiments, the gas purge device 600 further includes a sensor660. The sensor 660 is configured to generate a sensing signal bysensing a humidity and/or a concentration of the gas in the FOUP 100.FIG. 10 illustrates a block diagram of a gas gate 620 with the sensor660 according to some embodiments of the present disclosure. Similar tothe block diagram shown in FIG. 9 , as illustrated in FIG. 10 , thecontroller 630 is further electrically coupled to the sensor 660 forreceiving the sensing signal.

In some embodiments, the controller 630 is able to control the MFCs 621a, 621 b, 622 a, 622 b, 623 a, 623 b, 624 a and 624 b to adjust the gasflow based on the received sensing signal. For example, when theconcentration of the gas (in the FOUP 100) provided by the gas source600 a exceeds a pre-determined value during the cleaning process, thesensor 660 generates the sensing signal indicating that theconcentration of the gas from the gas source 600 a is too high. Thecontroller 630 receives the sensing signal and controls at least one MFCwhich is connected to the gas source 600 a to decrease the gas flow, soas to decrease the concentration of the gas in the FOUP 100 to adjustthe process back to desired conditions.

In some embodiments, the definitions (intake or exhaust) of the ports121 to 124 vary with different processes and also vary with differentFOUPs. FIG. 11 to FIG. 14 illustrate the gas purge device 600 beingoperated under different definitions of the ports 121 to 124. It shouldbe noted that only the gas gate 620, the bottom 120 a of the FOUP 100,the gas source 600 a and the gas tank 600 b are illustrated in FIG. 11to FIG. 14 , and other components are omitted to facilitateunderstanding.

Reference is made to FIG. 11 . In some embodiments, the FOUP 100 onlyneeds the port 121 and the port 123 to perform the process. In suchembodiments, the FOUP 100 only uses the port 121 and the port 123.Therefore, the nozzles 611 and 613 are connected to the ports 121 and123, respectively, and the nozzles 612 and 614 are idle.

In the embodiment of FIG. 11 , the controller 630 determines that numberof exhaust ports is one and the number of intake ports is one. Thecontroller 630 controls the switch unit 621 to select the gas tank 600 bfor removing the gas from the FOUP 100 through the port 121, andcontrols the switch unit 623 to select the gas source 600 a forproviding the gas to the FOUP 100 through the port 123.

The MFC 621 b is configured to control the gas flow from the port 121,and the MFC 621 a is idle or sets the gas flow to 0. The MFC 623 a isconfigured to control the gas flow from the gas source 600 a, and theMFC 623 b is idle or sets the gas flow to 0. Because the nozzle 612 andthe nozzle 614 are not used, the MFCs 622 a, 622 b, 624 a and 624 b areidle or set the gas flows to 0. In other words, the gas pathways fromthe gas source 600 a to the ports 122 and 124 and the gas pathways fromthe ports 122 and 124 to the gas tank 600 b are disconnected. The greylines in FIG. 11 indicate that there are no gas pathways therebetween.

Reference is made to FIG. 12 . In some embodiments, the FOUP 100 needstwo intake ports and two exhaust ports to perform the process. In theembodiment of FIG. 12 , the controller 630 determines that the number ofexhaust ports is two and the number of intake ports is two. Thecontroller 630 controls the switch unit 621 and the switch unit 624 toselect the gas tank 600 b for removing the gas from the FOUP 100 throughthe port 121 and the port 124, respectively, and controls the switchunit 622 and the switch unit 623 to select the gas source 600 a forproviding the gas to the FOUP 100 through the port 122 and the port 123,respectively.

The MFC 621 b is configured to control the gas flow from the port 121,and the MFC 621 a is idle or sets the gas flow to 0. The MFC 624 b isconfigured to control the gas flow from the port 124, and the MFC 624 ais idle or sets the gas flow to 0. The MFC 622 a is configured tocontrol the gas flow from the gas source 600 a, and the MFC 622 b isidle or sets the gas flow to 0. The MFC 623 a is configured to controlthe gas flow from the gas source 600 a, and the MFC 623 b is idle orsets the gas flow to 0. In other words, the gas pathways from the gassource 600 a to the switch units 621 and 624 are disconnected, and thegas pathways from the switch units 622 and 623 to the gas tank 600 b aredisconnected. The grey lines in FIG. 12 indicate that there are no gaspathways therebetween.

Reference is made to FIG. 13 . In some embodiments, the FOUP 100 needsone intake port and three exhaust ports to perform the process. In theembodiment of FIG. 13 , the controller 630 determines that number ofexhaust ports is three and the number of intake ports is one. Thecontroller 630 controls the switch unit 621, the switch unit 622 and theswitch unit 624 to select the gas tank 600 b for removing the gas fromthe FOUP 100 through the port 121, the port 122 and the port 124,respectively, and controls the switch unit 623 to select the gas source600 a for providing the gas to the FOUP 100 through the port 123.

The MFC 621 b is configured to control the gas flow from the port 121,and the MFC 621 a is idle or sets the gas flow to 0. The MFC 622 b isconfigured to control the gas flow from the port 122, and the MFC 622 ais idle or sets the gas flow to 0. The MFC 624 b is configured tocontrol the gas flow from the port 124, and the MFC 624 a is idle orsets the gas flow to 0. The MFC 623 a is configured to control the gasflow from the gas source 600 a, and the MFC 623 b is idle or sets thegas flow to 0. In other words, the gas pathways from the gas source 600a to the switch units 621, 622 and 624 are disconnected, and the gaspathway from the switch unit 623 to the gas tank 600 b is disconnected.The grey lines in FIG. 13 indicate that there are no gas pathwaystherebetween.

Reference is made to FIG. 14 . In some embodiments, the FOUP 100 needsthree intake ports and one exhaust port to perform the process. In theembodiments of FIG. 14 , the controller 630 determines that number ofexhaust ports is one and the number of intake ports is three. Thecontroller 630 controls the switch unit 621 to select the gas tank 600 bfor removing the gas from the FOUP 100 through the port 121, andcontrols the switch unit 622, the switch unit 623 and the switch unit624 to select the gas source 600 a for providing the gas to the FOUP 100through the port 122, the port 123 and the port 124, respectively.

The MFC 621 b is configured to control the gas flow from the port 121,and the MFC 621 a is idle or sets the gas flow to 0. The MFC 622 a isconfigured to control the gas flow from the gas source 600 a, and theMFC 622 b is idle or sets the gas flow to 0. The MFC 623 a is configuredto control the gas flow from the gas source 600 a, and the MFC 623 b isidle or sets the gas flow to 0. The MFC 624 a is configured to controlthe gas flow from the gas source 600 a, and the MFC 624 b is idle orsets the gas flow to 0. In other words, the gas pathway from the gassource 600 a to the switch unit 621 is disconnected, and the gaspathways from the switch units 622, 623 and 624 to the gas tank 600 bare disconnected. The grey lines in FIG. 14 indicate that there are nogas pathways therebetween.

The abovementioned operations of the gas purge device 600 in FIG. 11 toFIG. 14 are provided for illustrative purposes. Various operations ofthe gas purge device 600 are within the contemplated scope of thepresent disclosure. For example, in various embodiments, the FOUP 100needs two intake ports and one exhaust port to perform the process.

Reference is made to FIG. 15 . In some embodiments, the wafers 105further need an additional gas source 600 c and/or gas source 600 d toperform the cleaning process, in which the gas provided by the gassource 600 c and the gas source 600 d is different from the gas providedby the gas source 600 a. The gas purge device 600 is further coupled tothe gas source 600 c and the source 600 d.

In the embodiment of FIG. 15 , the gas gate 620 further includes an MFC621 c coupled between the switch unit 621 and the gas source 600 c, andincludes an MFC 621 d coupled between the switch unit 621 and the gassource 600 d. When the port 121 is determined to be an intake port, theswitch unit 621 is configured to select the gas source 600 a, the gassource 600 c, or the gas source 600 d for providing the gas, and the MFC621 a, the MFC 621 c or the MFC 621 d is configured to control the gasflow into the port 121.

The gas gate 620 further includes an MFC 622 c, an MFC 622 d, an MFC 623c, an MFC 623 d, an MFC 624 c and an MFC 624 d (not shown) coupled tothe switch units 622, 623 and 624. The MFCs 622 c, 622 d, 623 c, 623 d,624 c and 624 d are similar to the MFC 621 c and the MFC 621 d;therefore, the descriptions of the MFCs 622 c, 622 d, 623 c, 623 d, 624c and 624 d are not repeated herein. Also, the MFCs 622 c, 622 d, 623 c,623 d, 624 c and 624 d are omitted from FIG. 15 for simplicity.

In some embodiments, the controller 630 is implemented outside of thegas gate 620, as illustrated in FIG. 16 . The controller 630 may beshared with other semiconductor equipment.

Reference is made to FIG. 17 to FIG. 20 . FIG. 17 to FIG. 20 areflowcharts of the gas purge method 1700 according to some embodiments ofthe present disclosure. As illustrated in FIG. 17 , the method 1700includes operations S1710, S1720 and S1730. Detailed operations of thegas purge method 1700 are described below.

In operation S1710, the FOUP 100 with the wafer 105 inside is receivedby the gas purge device 600. In operation S1720, the gas purge device600 performs the configuration of the cleaning process. In operationS1730, the gas purge device 600 preforms the cleaning process to cleanthe wafers 105 in the FOUP 100 based on the configuration of thecleaning process.

In some embodiments as shown in FIG. 18 , the operation S1710 mayinclude operation S1711. In operation S1711, the clamper clamps thecoupling groove 125 of the FOUP 100 and the mechanism 640 of the gaspurge device 600.

In some embodiments as shown in FIG. 19 , the operation S1720 mayinclude operations S1721, S1722, S1723 and S1724. In operation S1721,the gas purge device 600 determines the number of intake ports for thegas source 600 a and the number of exhaust ports for the gas tank 600 b.In operation S1722, the gas purge device 600 determines the gas flowfrom the gas source 600 a and the gas flow to the gas tank 600 b. Inoperation S1723, the gas purge device 600 determines the number ofintake ports for the gas source 600 c. In operation S1724, the gas purgedevice 600 determines the gas flow from the source 600 c. In someembodiments, the operation S1720 may further determine the number ofintake ports for the gas source 600 d, and configured to determine thegas flow from the gas source 600 d.

In some embodiments as shown in FIG. 20 , the operation S1730 mayinclude operations S1731, S1732, S1733, S1734, S1735, S1736 and S1737.In operation S1731, the gas purge device 600 controls the correspondingswitch units connected to the intake ports to select the gas source 600a for providing the gas to the FOUP 100. In operation S1732, the gaspurge device 600 controls the corresponding switch units connected tothe exhaust ports to select the gas tank 600 b for receiving the gasfrom the FOUP 100. In operation S1733, the gas purge device 600 controlsthe corresponding switch units connected to the intake ports to selectthe gas source 600 c for providing the gas to the FOUP 100. In operationS1734, the gas purge device 600 sets the corresponding MFC to cause thedetermined gas flow. In operation S1735, the gas purge device 600provides the gas from the gas source 600 a to the FOUP 100 through thecorresponding intake ports. In operation S1736, the gas purge device 600provides the gas from the gas source 600 c to the FOUP 100 through thecorresponding intake ports. In operation S1737, the gas purge device 600receives the gas from the FOUP 100 through the corresponding exhaustports. In some embodiments, the operation S1730 may be furtherconfigured to control the corresponding switch unit connected to theintake port to select the gas source 600 d providing the gas to the FOUP100, and further configured to set the corresponding MFC to cause adetermined gas flow from the gas source 600 d.

In some approaches, the wafer containers have different configurationssuch as different numbers of ports for gas flow. When a purge deviceperforms a purge process on a different wafer container, the purgedevice must undergo hardware modification to comply with requirements ofthe different wafer containers. However, hardware modification iscostly. The cost of the purge process is thus increased due to thedifferent wafer containers.

Compared to the above approaches, in some embodiments of the presentdisclosure, the gas purge device 600 and the gas purge method 1700 areable to control the switch units 621 to 624 to select the gas source 600a or the gas tank 600 b, so as to provide the gas to the FOUP 100 orremove the gas from the FOUP 100. The hardware modification isunnecessary even when the FOUPs 100 have different configurations.Therefore, using the gas purge device 600 and the gas purge method 1700can decrease the cost of the process and reduce the time required forhardware modification.

One aspect of the present disclosure provides a gas purge device,including a first nozzle and a gas gate. The first nozzle is coupled toa FOUP through a first port of the FOUP. The gas gate is coupled to thefirst nozzle via a first pipe. The gas gate includes an MFC, a secondMFC and a first switch unit. The first MFC is configured to control afirst flow of a first gas. The second MFC is configured to control asecond flow of a second gas. The first switch unit is coupled to thefirst MFC and the second MFC, and configured to provide the first gas tothe first nozzle through the first pipe or receive the second gas fromthe first nozzle through the first pipe according to a processconfiguration.

Another aspect of the present disclosure provides a method including thefollowing operations: receiving a FOUP with wafers therein by a gaspurge device; determining a first number of first intake ports of thegas purge device and a second number of second exhaust ports of the gaspurge device; and, based on the first number and the second number,cleaning the wafers in the FOUP. Cleaning the wafers includes:providing, by a gas gate of the gas purge device, a first flow of afirst gas through the first intake ports to the FOUP; receiving, by thegas gate, a second flow of a second gas from the FOUP through the secondexhaust ports.

Although the present disclosure and its advantages have been describedin detail, it should be understood that various changes, substitutionsand alterations can be made herein without departing from the spirit andscope of the disclosure as defined by the appended claims. For example,many of the processes discussed above can be implemented in differentmethodologies and replaced by other processes, or a combination thereof.

Moreover, the scope of the present application is not intended to belimited to the particular embodiments of the process, machine,manufacture, composition of matter, means, methods and steps describedin the specification. As one of ordinary skill in the art will readilyappreciate from the present disclosure, processes, machines,manufacture, compositions of matter, means, methods or steps, presentlyexisting or later to be developed, that perform substantially the samefunction or achieve substantially the same result as the correspondingembodiments described herein, may be utilized according to the presentdisclosure. Accordingly, the appended claims are intended to includewithin their scope such processes, machines, manufacture, compositionsof matter, means, methods and steps.

What is claimed is:
 1. A gas purge device, comprising: a first nozzlecoupled to a front-opening unified pod (FOUP) through a first port ofthe FOUP; and a gas gate coupled to the first nozzle via a first pipe,wherein the gas gate comprises: a first mass flow controller (MFC)configured to control a first flow of a first gas; a second MFCconfigured to control a second flow of a second gas; and a first switchunit coupled to the first MFC and the second MFC, and configured toprovide the first gas to the first nozzle through the first pipe orreceive the second gas from the first nozzle through the first pipeaccording to a process configuration; wherein the gas purge device isconfigured to provide the first gas to a plurality of wafers in theFOUP, and the wafers are 12-inch and/or 18-inch wafers; wherein thefirst switch unit comprises: a first valve configured to be opened toprovide the first gas to the first nozzle; and a second valve configuredto be opened to receive the second gas from the first nozzle; whereinwhen the first valve is open, the second valve is closed, and when thefirst valve is closed, the second valve is open.
 2. The gas purge deviceof claim 1, further comprising: a second nozzle coupled to the FOUPthrough a second port of the FOUP; wherein the gas gate is furthercoupled to the second nozzle via a second pipe, and the gas gate furthercomprises: a third MFC configured to control a third flow of the firstgas; a fourth MFC configured to control a fourth flow of the second gas;and a second switch unit coupled to the third MFC and the fourth MFC,and configured to provide the first gas to the second nozzle through thesecond pipe or receive the second gas from the second nozzle through thesecond pipe according to the process configuration.
 3. The gas purgedevice of claim 2, wherein when the first gas is provided to the firstnozzle by the first switch unit, the second gas is received from thesecond nozzle by the second switch unit.
 4. The gas purge device ofclaim 2, further comprising: a third nozzle coupled to the FOUP througha third port of the FOUP; and a fourth nozzle coupled to the FOUPthrough a first port of the FOUP, wherein the gas gate is furthercoupled to the third nozzle and the fourth nozzle via a third pipe and afourth pipe, respectively, and the gas gate further comprises: a fifthMFC configured to control a fifth flow of the first gas; a sixth MFCconfigured to control a sixth flow of the second gas; a seventh MFCconfigured to control a seventh flow of the first gas; an eighth MFCconfigured to control an eighth flow of the second gas; a third switchunit coupled to the fifth MFC and the sixth MFC, and configured toprovide the first gas to the third nozzle through the third pipe or toreceive the second gas from the third nozzle through the third pipeaccording to the process configuration; and a fourth switch unit coupledto the seventh MFC and the eighth MFC, and configured to provide thefirst gas to the fourth nozzle through the fourth pipe or to receive thesecond gas from the fourth nozzle through the fourth pipe according tothe process configuration.
 5. The gas purge device of claim 4, whereinthe first gas is provided to the first nozzle by the first switch unit,and the second gas is received from the second nozzle, the third nozzleand the fourth nozzle by the second switch unit, the third switch unitand the fourth switch unit, respectively.
 6. The gas purge device ofclaim 4, wherein the first gas is provided to the first nozzle and thethird nozzle by the first switch unit and the third switch unit,respectively, and the second gas is received from the second nozzle andthe fourth nozzle by the second switch unit and the fourth switch unit,respectively.
 7. The gas purge device of claim 4, wherein the first gasis provided to the first nozzle, the third nozzle and the fourth nozzleby the first switch unit, the third switch unit and the fourth switchunit, respectively, and the second gas is received from the secondnozzle by the second switch unit.
 8. The gas purge device of claim 4,wherein the gas gate further comprises: a controller configured tocontrol the first switch unit, the second switch unit, the third switchunit, the fourth switch unit, the first MFC, the second MFC, the thirdMFC, the fourth MFC, the fifth MFC, the sixth MFC, the seventh MFC andthe eighth MFC.
 9. The gas purge device of claim 8, wherein thecontroller is further configured to receive a sensing signal generatedby a sensor, wherein the sensor is configured to sense a humidity, aconcentration of the first gas, and/or a concentration of the second gasof the FOUP, wherein the controller further controls the first switchunit, the second switch unit, the third switch unit, the fourth switchunit, the first MFC, the second MFC, the third MFC, the fourth MFC, thefifth MFC, the sixth MFC, the seventh MFC and the eighth MFC accordingto the sensing signal.
 10. The gas purge device of claim 9, wherein thecontroller is implemented by a programmable logic controller (PLC). 11.The gas purge device of claim 1, further comprising: a mechanismconfigured to be clamped and connected to the FOUP.
 12. The gas purgedevice of claim 1, wherein the gas gate further comprises: a ninth MFCconfigured to control a ninth flow of a third gas, wherein the third gasis different from the first gas and the second gas, wherein the firstswitch unit is further coupled to the ninth MFC, and configured toprovide the third gas to the first nozzle through the first pipe. 13.The gas purge device of claim 12, wherein the gas gate furthercomprises: a tenth MFC configured to control a tenth flow of a fourthgas, wherein the fourth gas is different from the first gas, the secondgas and the third gas, wherein the first switch unit is further coupledto the tenth MFC, and configured to provide the fourth gas to the firstnozzle through the first pipe.
 14. A gas purging method, comprising:receiving, by a gas purge device, a front-opening unified pod (FOUP)with wafers therein; determining a first number of first intake ports ofthe FOUP and a second number of second exhaust ports of the FOUP; andbased on the first number and the second number, cleaning the wafers inthe FOUP, wherein cleaning the wafers comprises: providing, by a gasgate of the gas purge device, a first flow of a first gas through thefirst intake ports to the FOUP; and receiving, by the gas gate, a secondflow of a second gas from the FOUP through the second exhaust ports. 15.The gas purging method of claim 14, wherein cleaning the wafers furthercomprises: controlling the first number of switch units connected to thefirst intake ports to select a first gas source for providing the firstgas to the FOUP; and controlling the second number of switch unitsconnected to the second exhaust ports to select a gas tank for receivingthe second gas from the FOUP.
 16. The gas purging method of claim 15,further comprising: determining the first flow of the first gas and thesecond flow of the second gas, wherein cleaning the wafers furthercomprises: setting the first number of first mass flow controllers(MFCs) to have a first overall flow equal to the first flow; and settingthe second number of second MFCs to have a second overall flow equal tothe second flow, wherein the first MFCs are connected to the first gassource, and the second MFCs are connected to the gas tank, and wherein asum of the first number and the second number is equal to 4, and thefirst number and the second are greater than
 0. 17. The gas purgingmethod of claim 14, further comprising determining a third number ofthird intake ports of the gas purge device, wherein cleaning the wafersfurther comprises: controlling the third number of switching unitsconnected to the third intake ports to select a second gas source forproviding the third gas to the FOUP; setting the third number of thirdMFCs to have a third overall flow equal to the third flow; andproviding, by the gas gate, the third flow of a third gas through thethird intake ports to the FOUP.
 18. The gas purging method of claim 14,wherein receiving the FOUP comprises: clamping the FOUP and the gaspurge device by a damper.